title: Removal of a dimeric form of surfactant protein C from mouse lungs: its acceleration by reduction.
abstract: Clearance of hydrophobic surfactant-associated protein C (SP-C) and its dimeric form ([SP-C]2) was investigated. SP-C and [SP-C]2 obtained from proteinosis patients were fluorescently labeled and were instilled into mouse lungs as lipid-protein complexes. [SP-C]2 was removed more slowly than SP-C, with apparent half-lives of 30 and 18 h, respectively. A significant amount of [SP-C]2 was removed as SP-C, and the conversion rate was 0.22 micrograms.h-1.mouse-1. By correcting the removal as SP-C, we obtained 38 h for a possible half-life of [SP-C]2. Conversion from SP-C to [SP-C]2 seemed very slow. Decrease in glutathione (GSH) in the lung inhibited the conversion of [SP-C]2 to SP-C and GSH-treatment of liposomes accelerated clearance of [SP-C]2. These results suggest that the removal of [SP-C]2 from lung is accelerated by reduction and that GSH acts as a reducing agent in the lung.
authors.affiliation: Department of Molecular Pathology, Kyoto University, Japan.
authors.forename: Z Y
authors.initials: ZY
authors.lastname: Li
authors.forename: Y
authors.initials: Y
authors.lastname: Suzuki
authors.forename: M
authors.initials: M
authors.lastname: Kurozumi
authors.forename: H Q
authors.initials: HQ
authors.lastname: Shen
authors.forename: C X
authors.initials: CX
authors.lastname: Duan
mesh_terms: D000818:Animals; D019281:Dimerization; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D005453:Fluorescence; D005978:Glutathione / Q000378:metabolism / Q000494:pharmacology; D006801:Humans; D007322:Instillation, Drug; D008081:Liposomes; D008168:Lung / Q000378:metabolism*; D051379:Mice; D008807:Mice, Inbred BALB C; D011486:Protein C / Q000378:metabolism* / Q000493:pharmacokinetics; D011649:Pulmonary Alveolar Proteinosis / Q000378:metabolism; D011663:Pulmonary Surfactants / Q000378:metabolism* / Q000493:pharmacokinetics; D014132:Trachea
chemical_list: D008081:Liposomes; D011486:Protein C; D011663:Pulmonary Surfactants; D005978:Glutathione